Carburetor



March 9, 1943. w. SCHWIE'R CARBURETOR 3l Sheets-Sheet 3 Filed' May 281941 Jczwielv v INVENTOR.

Patented Mar. 9, 1943 -UNITED STATES PTEN'E OFFICE This invention aimsto provide a carburetor characterized by novel means for controlling theidling flow of fuel and the running flow of fuel consonant-.ly with theoperation of an air controlling valve, the fuel being discharged througha nozzle, and a novel venturi and cone valve structure being providedfor regulating the downward now of air about the nozzle.

It is within the province of the disclosure to improve generally and toenhance the utility of devices of that type to which the presentinvention appertains.

With the above and other objects in view, which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed, may be made within thescope of what is claimed, without departing from the spirit of theinvention.

In the drawings:

Fig. 1 shows, in vertical section, a carburetor constructed inaccordance with the invention, parts being removed;

Fig. 2 is a side elevation;

Fig. 3 is a side elevation, at right angles to the showing of Fig. 2,'

Fig. 4 is a cross section on the line 4-4 of Fig. 1;

Fig. 5 is a perspective disclosing one of the shafts and the cam whichit carries.

The carburetor forming the subject matter ofl this application comprisesa tubular body I, including a bowl 2, connected by a tapered por- -tion3 with a reduced tubular neck 4, having an attaching ange 5.

A shaft 6 is mounted to rock in the upper portion of the bowl 2 andcarries an air valve :1,

the bell and the tapered portion 3 of ther body I.

A tubular nozzle carrier I5 is located in the vertical axis of the bodyI. The means for supporting the nozzle carrier |5 can be moreconveniently described hereinafter. A nozzle I6 is threaded into thenozzle carrier I5, and is provided with a closed top. Intermediate itsends, the nozzle I6 is reduced, to form a circumscribing Space I1 Withinthe nozzle carrier I5. The nozzle I6 is equipped with transverse portsI8, leading from the space Il to the bore of the nozzle I 6.

The lower portion of the nozzle I6 is surrounded by a downwardly taperedcone valve I3,

the top 2E of which is supplied with openings 2|.v

The top 23 of the cone valve I9 has a tubular neck 22, whereby the conevalve is mounted on the nozzle carrier I5 for limited vertical movement.The neckY 22 is supplied with vertically elongated slots 213, receivingpins 24, mounted in the nozzle carrier I5. The cone vvalve I9 isvadapted to engage the Venturi member I Il, Vat the restricted openingwhich is located at the juncture between the bell I I and the extensionI2.

The nozzle carrier I5 has a lateral arm 25, engaging the inner surfaceof the bowl 2. The arm 25 of the nozzle carrier I5 is provided with alower chamber 25 and an upper chamber 21, connected by a passage 28.Access is had to the chamber 2'I and to the passage 28 and to thechamber 26 by removing a closure plug 2S that is threaded into the arm25. Fuel is delivered into the lower chamber 23 through a conduit 3|),mounted in the bowl 2 and in the arm 25.

A tubular guide 3| extends through the lower chamber 26, the inner endof the guide being threaded into the arm 25 of the nozzle carrier I 5,the guide being provided at its outer end with aV head 32, which engagesthe outer surface of the bowl 2. Thus, the nozzle carrier |5 and its arm25 are secured within the bowl. The guide 3| is provided with transverseports 33, communicating with the lower chamber 25. At the inner end ofthe bore of the guide 3| there is a valve seat 34. A port in the nozzlecarrier l5 leads from the valve seat 34 to the space` II about thenozzle I6. A needle valve 36 is slidably mounted in the guide 3| andcooperates with the seat 34.

As to the upper chamber 21, the parts last hereinbefore `described areduplicated, and reference to them may be reduced to a mere catalogue.They comprise a tubular guide 4| having a head 42, the guide beingprovided with ports :i3 and a valve seat 44. The port corresponds to theport 35, and the needle valve is shown at 46.

The numeral 41 marks a cross head, a pull spring 48 connecting thevlower part of the cross head with the carburetor body The needle valve36 is adjustably mounted in the cross head 41, but is held firmlythereto by the clamping nuts 49. A wear ring 50 is carried by the needlevalve 36 and abuts against the innermost nut 49.

The needle valve 46 passes through an enlarged hole 5I in the cross head41. An abutment nut 52 is threaded to a seat on theneedle valve 4S. Acompression spring 53 is interposed between the cross head 41 and theabutment nut 52. An adjusting nut 54 is threaded on the outer part ofthe needle valve 46 and engages the outer surface of the cross head 41under the thrust of the spring 53.

A crank arm 55 is held for adjustment, by means of a set screw 56, onthe outer part of the shaft 6 which carries the air valve 1. A link 51is provided. 'I'he link 51 embodies means 58 whereby the length of itcan be changed. The

upper part of the link 51 is pivoted at 59 to thel crank arm 55 on theshaft 6.

The lower part of the link 51 is pivoted at 60 to a crank arm 6I on atransverse shaft` 62, f

mounted to rock in a tubular bearing 63 whichv forms part of a bracket64, xed on the bowl 2 of the carburetor body I. A forked cam 65 is heldfor adjustment on the shaft 62, by means of a set screw 66. The cam 65straddles the lower needle valve 35 and bears against the wear ring 50.

By an adjustment secured through a proper manipulation of theadjustingnut 54, and the nuts 49, the idling needle valve 46 may becaused to be open, to such a degree as to permit idling, whilst theneedlevalve 46 is closed under the pull of the spring 48 on the crosshead 41.

Then there exists an open idling passage including the conduit 36, thelower chamber 26, the ports 33 in the guide 3l, the opening 28, theupper chamber 21, the ports 43 in the guide 4I, the port 45, the space31 about the nozzle I6, the nozzle ports I8, and the bore of the nozzleI6.

The running passage is closed by the needle valve 36 and includes theconduit 36, the lower chamber 26, the ports 33 in the guide 3I, the port35, the space 31 about the nozzle I6, the nozzle ports I6, and the boreof the nozzle I6.

When the shaft 6 is operated by the means shown at 8 9, the needle valve36 is retracted to open the running passage, and the needle valve 46 isretracted to open the idling passage more widely, by a train of partsincluding the shaft 6, the crank arm 55, the link 51, the crank arm 6I,the shaft 62 andthe cam 65, which transmits movement to the needlevalves 36 and 46, in a way which will be clear from Fig. l of thedrawings. The valves 46 `and 36 move outwardly together.

In Fig. l, the needle valves 36 and 46 are shown open, in order todisplay the structure more clearly, but suppose that, by a properY ma-Vnipulation of the nut 54, the needle valve 46 is sodisposed that it willbe open when the needle valve 36 is closed. Due to engine suction, thereexists in the lower portion of the body I, a region 61 of low pressure.The venturi I0 does not move downwardly, responsive to low pressure inthe region 61, because the venturi is sustained by Athe spring I4, thevalve 1 being opened only enough to supply air for idling purposes, andthe pressure in the bowl 2 being insucient to overcome the action of thespring I4.

There is now a strong suction through the passage beginning with thebore of the nozzle I6, and including the port 45, the bore of the guide4I, the ports 43, the opening 28, and the chamber 26, fuel supplied bythe conduit 3U being drawn upwardly and discharged into the bore of thenozzle I6.

As the air valve 1 is opened, atmospheric Dressure above the bell II ofthe venturi I0 increases. The venturi III moves downwardly, against theaction of the spring I4, and the cone valve I9 at first moves downwardlywith it. The first thing that takes place is a spacing of the cone valveI9 from the lower end portion of the nozzle I6, and a downward passageof air is afforded, through the openings 2| in the top of the cone valveand in the space that exists between the lower part of the cone valveand the lower part of the nozzle I6.

As the venturi l0 continues to move downwardly, responsive toatmospheric pressure above it, the downward movement of the cone valveI9 ultimately is stopped by the pins 23 on the nozzle carrier I5 andthen there is created a second air passage, to wit, a passage betweenthe flared bell II of the Venturi member I6 and the cone valve I9.

Broadly considered, the operation of the venturi I and the cone valve I9is described in my Patent No. 2,163,499, issued June 20, 1939, althoughin that patent, a downward movement of the venturi is brought aboutmechanically,

When the cam 65 is moved toward and to the position of Fig. l, thevalves 36 and 46 move inwardly together. The valve 36 closes, to shutoff the running supply, before the valve 46 closes completely, the valve46 remaining open sufliciently for idling purposes, it being recalledthat, as has been set forth herenbefore, by a proper manipulation of thenut 54 the valve 46 has a retracted position with respect to the valve36. The purpose of the spring 53 is to draw the nut 54against the crosshead 41, thereby aiding in preventing the nut 54 from unthreading. Thespring 53 permits a longitudinal adjustment of the valve 46 to be made,through the instrumentality of a single nut, namely the nut 54..'

What is claimed is:

A carburetor comprising a body, a nozzle car-y an idling valve, and thelower valve being a run' ning valve, an air controlling valve in thebody, above the nozzle, a cross head, means for connecting the lowerneedle valve fixedly but adjustably to the cross head, the upper needlevalve passing through the cross head, for longitudinal slidingadjustment, spring means connected to the cross head for closing thevalves, and mechanism operated in consonance with the air Avalve foropening the upper and lower needle valves.

WILLIAM SCHWIER.

